src/network/networkd.c

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2
   3 #include <netinet/in.h>
   4 #include <sys/stat.h>
   5 #include <sys/types.h>
   6
   7 #include "sd-daemon.h"
   8 #include "sd-event.h"
   9
  10 #include "bus-log-control-api.h"
  11 #include "capability-util.h"
  12 #include "daemon-util.h"
  13 #include "firewall-util.h"
  14 #include "main-func.h"
  15 #include "mkdir-label.h"
  16 #include "networkd-conf.h"
  17 #include "networkd-manager-bus.h"
  18 #include "networkd-manager.h"
  19 #include "service-util.h"
  20 #include "signal-util.h"
  21 #include "strv.h"
  22 #include "user-util.h"
  23
  24 static int run(int argc, char *argv[]) {
  25         _cleanup_(manager_freep) Manager *m = NULL;
  26         _unused_ _cleanup_(notify_on_cleanup) const char *notify_message = NULL;
  27         int r;
  28
  29         log_setup();
  30
  31         r = service_parse_argv("systemd-networkd.service",
  32                                "Manage and configure network devices, create virtual network devices",
  33                                BUS_IMPLEMENTATIONS(&manager_object, &log_control_object),
  34                                argc, argv);
  35         if (r <= 0)
  36                 return r;
  37
  38         umask(0022);
  39
  40         if (argc != 1)
  41                 return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "This program takes no arguments.");
  42
  43         /* Drop privileges, but only if we have been started as root. If we are not running as root we assume all
  44          * privileges are already dropped and we can't create our runtime directory. */
  45         if (geteuid() == 0) {
  46                 const char *user = "systemd-network";
  47                 uid_t uid;
  48                 gid_t gid;
  49
  50                 r = get_user_creds(&user, &uid, &gid, NULL, NULL, 0);
  51                 if (r < 0)
  52                         return log_error_errno(r, "Cannot resolve user name %s: %m", user);
  53
  54                 /* Create runtime directory. This is not necessary when networkd is
  55                  * started with "RuntimeDirectory=systemd/netif", or after
  56                  * systemd-tmpfiles-setup.service. */
  57                 r = mkdir_safe_label("/run/systemd/netif", 0755, uid, gid, MKDIR_WARN_MODE);
  58                 if (r < 0)
  59                         log_warning_errno(r, "Could not create runtime directory: %m");
  60
  61                 r = drop_privileges(uid, gid,
  62                                     (1ULL << CAP_NET_ADMIN) |
  63                                     (1ULL << CAP_NET_BIND_SERVICE) |
  64                                     (1ULL << CAP_NET_BROADCAST) |
  65                                     (1ULL << CAP_NET_RAW));
  66                 if (r < 0)
  67                         return log_error_errno(r, "Failed to drop privileges: %m");
  68         }
  69
  70         /* Always create the directories people can create inotify watches in.
  71          * It is necessary to create the following subdirectories after drop_privileges()
  72          * to support old kernels not supporting AmbientCapabilities=. */
  73         FOREACH_STRING(p,
  74                        "/run/systemd/netif/links/",
  75                        "/run/systemd/netif/leases/") {
  76                 r = mkdir_safe_label(p, 0755, UID_INVALID, GID_INVALID, MKDIR_WARN_MODE);
  77                 if (r < 0)
  78                         log_warning_errno(r, "Could not create directory '%s': %m", p);
  79         }
  80
  81         r = manager_new(&m, /* test_mode = */ false);
  82         if (r < 0)
  83                 return log_error_errno(r, "Could not create manager: %m");
  84
  85         r = manager_setup(m);
  86         if (r < 0)
  87                 return log_error_errno(r, "Could not set up manager: %m");
  88
  89         r = manager_parse_config_file(m);
  90         if (r < 0)
  91                 log_warning_errno(r, "Failed to parse configuration file: %m");
  92
  93         r = manager_load_config(m);
  94         if (r < 0)
  95                 return log_error_errno(r, "Could not load configuration files: %m");
  96
  97         r = manager_enumerate(m);
  98         if (r < 0)
  99                 return r;
 100
 101         r = manager_start(m);
 102         if (r < 0)
 103                 return log_error_errno(r, "Could not start manager: %m");
 104
 105         log_info("Enumeration completed");
 106
 107         notify_message = notify_start(NOTIFY_READY, NOTIFY_STOPPING);
 108
 109         r = sd_event_loop(m->event);
 110         if (r < 0)
 111                 return log_error_errno(r, "Event loop failed: %m");
 112
 113         return 0;
 114 }
 115
 116 DEFINE_MAIN_FUNCTION(run);